PARIS, March 6 (Reuters) - French power utility Engie is looking at big acquisitions that will generate cash, in a strategy switch following the sale of 15 billion euros of assets that have shrunk its earnings base, according to two sources close to the company.

Between 2012 and 2016, Engie's revenue fell by a third, from 97 billion euros ($119 billion) to 66.6 billion, and analysts expect it to have dropped further during 2017. Over the same period, core earnings have slumped, from 17 billion euros in 2012 to a forecast 9.3 billion euros at end 2017.

Engie's stock has followed the same pattern, dropping more than 40 percent from 2012 highs. Its $39 billion market value puts the one-time top European utility way behind peers Iberdrola and Enel, worth $61 billion and $48 billion respectively.

New Engie CEO Isabelle Kocher, appointed in May 2016, has reinvested part of the proceeds from sales of fossil fuel related assets in a string of smaller renewable energy, power grids and energy services assets.

But the acquisitions have not made up for the lost earnings so far and investors are hoping to get more clarity on Engie's strategy at the release of 2017 earnings on Thursday.

With the stock price lower than when she took charge, Kocher is cautiously considering bigger deals in a bid to restore earnings flow and regain investor confidence, the sources said.

A source close to the board told Reuters that management is presenting potential major acquisitions to the board every three months. The last such meeting took place at the end of 2017.

"Selling the 'old-world' assets has blown a hole in the earnings and it is not going to be filled with renewables, so Kocher is on the lookout for an acquisition," the source said.

The sources declined to name possible acquisition targets, but bankers said Dutch utility Eneco could prove attractive. Eneco's owners want to pursue a private sale to another industry player in coming months, Reuters has reported.

Engie declined to comment.

GROWTH ENGINES

An investment banker who has worked on several deals for Engie said the arrival of Solvay CEO Jean-Pierre Clamadieu, who will take over as chairman of Engie's board in May, could speed up the switch in strategy.

"The way Engie is run may change in coming months. Engie has to do something big," he said.

Shortly after he was nominated in February, Clamadieu said on French TV that Kocher's strategy was "coherent", but that Engie needed to "identify growth engines and consider external growth".

A first wave of asset sales in 2012-15 was aimed at reducing debt, but Kocher's strategy is to sell and reinvest.

By late 2017, Engie had completed nearly 90 percent of her divestment plan with the sale of its upstream liquefied natural gas assets for $1.5 billion, its oil and gas exploration and production business for $3.9 billion and the Loy Yang B coal-fired power station in Australia for $835 million.

How Engie has reinvested, or will reinvest, the proceeds of the sales, and how much cash is left, is less clear.

While asset sales were big chunks counted in billions, acquisitions have been mainly counted in millions, like the 430 million euro for solar energy firm SolaireDirect and the $762 million for 40 percent in Dubai air-conditioning firm Tabreed.

Last year in May, sources said Germany's RWE and Engie had studied the possibility of RWE swapping its renewables and grids unit Innogy in exchange for a stake in Engie.